Roller-presser mechanism for sewing machines



WITESSESp 1 BY 1 Sept. 15, 1931. E, w JO N 1,823,546

ROLLER PRESSER MECHANISM FOR SEWING MACHINES Filed Aug. 2, 1925 INVENTO R Edwin W'Jafilwala ATTORNEY Patented Sept. 15, 1931 EDWIN W. JOHNSON,

NECTICU'I, ASSIGNOR TO THE NEW JERSEY, A CORPORATION or NICHOLS, TBUMBELL Townsnir,

SINGER manurnocrunme or new JERSEY FAIBFIELD COUNTY, con- ROLLER-PRESSER MECHANISM FOR SEWING MACHINES This invention relates to improvements in rollerresser mechanisms for sewingv ma chines and has for its object to provide efficient means for preventing retrograde rotation of the presser-roller substantially in stantaneously upon its initiation. I

In the use of sewing machines having roller-pressers freely rotatable during the advance of the work past the stitch'forming mechanism, a frequent occurrence is a retro: grade rotation of the presser-roller induced by obstructions to the passage under-the presser-roller of Work having heavy cross seams and the like. This retrograde rotation of the presser-roller delays theadvance of the work to an extent resulting in the formation of shortened stitches and even in the cutting of stock such as leather by the bunched penetrations of the stock by the needle. This condition is considerably a gravated by a presser mechanism in which the presser-roller has a very free rotation as in ball-bearing journaled presser-rollers and also by the employment in high speed machines of eccentric-actuated feed-dogs, having an elliptical path of movement and tending to back-feed the work during the return stroke of the feed-dog.

In a preferred embodiment of the present improvement, a ball-bearing 1ournaled presser-roller is prevented from retrograde rotation by a back-stop device comprising a ball movable longitudinally of a socket afforded by an apertured boss upon the presser-roller carrying arm. The ball is spring pressed in a direction to project through an opening in the side wall of the socket formed by truncating the lower end of the socket, the projecting portion of the ball engaging the flattenedouter face of the presser-roller. The ball socket comprises a guideway inclined to the ball-engaged face of the presser-roller and therefore any retrograde rotation of the presser-roller is promptly prevented by the jamming of the ball between the presserroller and the ball socket.

The presser-roller is prevented from yielding laterally under the thrust of the ball by an opposing member adjusted into position to barely clear the inner face of the presser- Application filed August 2, 1929.- Serial No. 382.895.-

roller at a the ball, thereby insuring efficient operation of the back-stop device. v

In the accompanying drawings, Fig. 1 is a view in side elevation of the present rollerpresser. and showing the needle-carrying bar of a sewing machine containing the improvement, Fig. 2 is a view in front elevation of the improvement, with the presser-wheel in section, Fig. 3 is a top-plan view of'thc roller-,pressjer, with thepresser-bar in section. Fig. 4; is a sectional view substantially on the line 4-4 of Fig. 1.

Referring to the drawings, presser containing a preferred embodiment of the present invention is of well known construction as commercially employed in a sewing machine having a cloth-plate 1 and a vertically reciprocatory needle-bar 2 carrying a needle 3.

The presser mechanism comprises the usual resser-roller or wheel 4' having a knurleg peripheral surface 5 and a lateral hub .6.-, The hub 6 provide spaced annular recesses as .8 and 9 for two sets of bearing-balls, as 10 and 11; The bear ng-balls l h e a' o ing Contact with a bearing cone 12 afforded by the head of a resser-wheel supporting screw 13, said screw-head having a flange 11 for retaining the balls 10 within the recess 8. Threaded upon the'screw 18 is a shouldered bearingcone 15 for the balls 11, the screw being itself threaded into the free end of a sup porting arm 16'and secured in the adjusted position of the bearing-cones by means of a nut 17. d

The pressersroller supporting arm 16 is securedin a recessed seat 18 in one sideof a presser arm bra k t .19, the arm se urmg means comprisi g a s rew 12 pas ng through an elongated aperture 21 in the arm 16 to provide for adjustment of the presserrol er in the direction of 'sean f rmationhe bracket 19 is prefera y suppo te n any wel -known manner by a Presser-bar. 22, whereby thepresser-roller m y be swung latral y ut of its operative posit on The presser-roller a face 23 bounded by the peripheral surface the roller" has an internal rib 7 to ha fla te ed out-er OOMI!ANY, or ELIZABETH, v

int substantially opposite to 5. Adjacent to said face 23 is disposed an apertured boss 24 formed upon the supporting-arm 16, the aperture or socket 25 of this boss constituting a guideway inclined down wardly toward said presser-roller face 23 and also inclined with respect to the axis of rotation of the presser-roller. Disposed within the boss-aperture 25 soas to be movable longitudinally thereof is a backstop member in the form of a ball 26 adapted to project through an opening 27 provided in the boss 24 by partially cutting it away. at its lower end. The back-stop ball 26 is yieldingly urged to engage the presser-roller face 23 by a spring 28 housed within the boss-aperture 25, the pressure of the spring being adjustable by means of a screw 29.

It will be apparent from the foregoing description that the presser-roller, as shown in Fig. l of the drawings, is free to rotate in I a clockwise direction to accommodate the usual advance of the work indicated by the arrow. This direction of rotation of the' presser-roller tends to push the ball 2611p wardly in the inclined boss-aperture against the action of the spring 28 and therefore away from the presser-roller face 28. However, retrograde rotation of the presser-roller is substantially instantaneously prevented by the induced roller-jamming action of the ball, as will be self evident. A

In order to insure eflicient operation of the back-stop device, the presser-roller 4 is prevented from yielding laterally under the thrust of the ball 26 by an opposing member comprising a screw 30 adjustably threaded into an ear 31 upon the bracket 19. The opposing screw 30 is preferably adjusted to have a minute clearance between the rounded end of the screw and the inner face 32 of the resser-roller at a point substantially opposite to the ball 26, the screw 30 being secured in adjusted position by means of a nut 33.

Having thus set forth the nature of the invention, what I claim herein is v l. A roller-presser mechanism for sewing machines, comprising a supporting bracket, a presser-roller rotatively journaled upon said bracket, and a back-stop member carried by said bracket in position to engage an outer face of said presser-roller, whereby to restrain the presser-roller against rotation inone direction, said back-stop member being bodily yieldable to permit free rotation of the resser-roller in the opposite direction.

2. roller-presser mechanism for sewing machlnes, comprising a supporting bracket, a presser-roller having a peripheral workengaging surface bounding a pair of side faces, means for journaling the presser-roll er upon said bracket for free rotation in one 1rection, and a back-stop member engaging one of said resser-roller side faces to prevent rotation of the resser-roller in the opposite direction.

3. A roller-presser mechanism for sewing machines, comprising a supporting bracket, a presser-roller journaled upon said bracket for free rotation in one direction, said presser-roller having a pair of side faces bounded by a peripheral work-engaging surface, a guideway upon said bracket inclined toward an adjacent side face of said presser-roller, a. back-stop member shiftably disposed in said guideway, and a spring yieldingly urging said back-stop member to engage said ,presser-roller face'to thereby prevent rotation of the presser-roller in one direction.

4. A roller-presser mechanism for sewing machines, comprising a supporting bracket, a presser-roller rotatively journalcd upon said bracket, a back-stop member carried by said bracket in osition to engage said presser-roller where y to restrain the presserroller againstrotation in one direction, and adjustable means preventing the presserroller from yielding bodily under the thrust of said back-stop member.

5. A roller-Presser, mechanism for sewing machines, comprising a supporting bracket, a presser-roller, a ball-bearing journal for said presser-roller upon the supporting bracket, a back-stop member restraining the Presser-roller against rotation in one direction, and adjustable means preventing the presser-roller from yielding bodily under the thrust of said back-stop member.

In testimony whereof, I have signed my name to this specification.

EDWIN W. JOHN SON. 

